ssh 报错Host key verification failed 或Ubuntu connect to serve 失败 通常是因为没有装ssh
sudo apt-get install openssh-server 就可以了，但是我这边是因为之前连上了，后面远程服务器改了密码，
之前保存的密码验证失败，这时候就要把保存的密码删掉，哪里删掉？？？
用Ubuntu connect to serve 就直接报错，用ssh就报下面的错，
ssh xxx@xxx.xxx.xxx.xxx
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Please contact your system administrator.
Add correct host key in /home/xxxxx/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /home/xxxxxx/.ssh/known_hosts:23
remove with: ssh-keygen -f "/home/xxxxx/.ssh/known_hosts" -R xxxx.xxxx.xxxx.xxxx
ECDSA host key for xxxx.xxxx.xxxx.xxxx has changed and you have requested strict checking.
Host key verification failed.
其实，只要打开 /home/xxxxx/.ssh/known_hosts ，把23行的删掉就可以，那个是密钥保存的，之后远程登录重新输入新的密码就可以了
